scholarly journals p-COUMARATES OF BETULA PENDULA (BETULACEAE) VEGETATIVE BUDS SESQUITERPENE ALCOHOLS

2020 ◽  
pp. 127-132
Author(s):  
Dmitriy Nikolaevich Vedernikov ◽  
Elizaveta Mihailovna Ipanova
Keyword(s):  
Antimicrobial Activity ◽  
Betula Pendula ◽  
Retention Indices ◽  
Methyl Tert Butyl Ether ◽  
Chromatographic Retention ◽  
Klebsiella Pneumonia ◽  
Alcoholic Extract ◽  
Butyl Ether ◽  
Vegetative Buds ◽  
Physico Chemical

The composition of coumarates sesquiterpene alcohols of Betula pendula Roth. birch vegetative buds was determined. Fraction was isolated from buds extract by preparative liquid chromatography. The extract was isolated by sequential extraction of an alcoholic extract of the buds with methyl tert-butyl ether. The new sesquiterpene derivatives were first detected in the birch vegetative buds. The structure of 6-hydroxyisocaryophyllene [(1R,4Z,6R,9S)-8-methylene-11,11-dimethylbicyclo[7.2.0]undec-4-ene-6-ol] trans-p-coumarate isolated from the birch buds was determined by NMR spectroscopy. The physico-chemical characteristics and NMR data of 6-hydroxyisocaryophyllene p-coumarate and others coumarates are demonstrated. The gas chromatographic retention indices of all identified compounds were determined. Birch buds contain derivatives of trans-coumaric acid. The antimicrobial activity of sesquiterpene alcohols coumarates was evaluated. The antimicrobial activity of sesquiterpene alcohols coumarates in relation to the following microorganisms: Escherichia coli, Proteus mirabilis, Staphylococcus aureus, Staphylococcus pneumonia and Klebsiella pneumonia was evaluated. The fraction of sesquiterpene alcohols coumarates showed activity against Staphylococcus epidermidis.

scholarly journals 6-Hydroxyisocaryophyllene and isocaryophyllenic acid from birches vegetative buds

2018 ◽  
pp. 115-122
Author(s):  
Dmitriy Nikolaevich Vedernikov ◽  
Svetlana Vitalievna Teplyakova ◽  
Olesya Valerievna Khoroshilova
Keyword(s):  
Betula Pendula ◽  
Retention Indices ◽  
Chromatographic Retention ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Data ◽  
Vegetative Buds ◽  
Physico Chemical ◽  
Gas Chromatographic Retention Indices ◽  
Chromatographic Retention Indices

The new isocaryophyllene derivatives were first detected in the birch vegetative buds. The structure of 6-hydroxyisocaryophyllene [(1R,4Z, 6R, 9S)-8-methylene-11,11-dimethylbicyclo[7.2.0]undec-4-ene-6-ol] isolated from the Betula pendula Roth. birch buds was determined by NMR spectroscopy.  The structures of caryophyllenic acid and isocaryphyllenic acid isolated from the Betula grandifolia Litv., B. albo-sinensis Burk., B. fusca Pall.ex Georg, B. obscura A. Kotula, B. litwinowii Doluch., B. hallii Howell, B. grandifolia Litv. birch buds was determined by X-ray diffraction analysis. The physico-chemical characteristics and NMR data of 6-hydroxyisocaryophyllene, epoxide of 6-hydroxyisocaryophyllene and all the isolated acids are given.  The gas chromatographic retention indices of all identified compounds were determined.

Capillary Gas-Chromatographic Retention Behavior and Physico-Chemical Properties of Underivatized Equine Estrogens

1995 ◽  
Vol 60 (5) ◽  
pp. 813-819 ◽  
Author(s):  
Jasmina Novakovic ◽  
Eva Tvrzická ◽  
Václav Všetečka ◽  
Vladimír Pouzar ◽  
Ladislav Feltl
Keyword(s):  
Dipole Moments ◽  
Chemical Properties ◽  
Retention Indices ◽  
Chromatographic Retention ◽  
Retention Behavior ◽  
Kováts Retention Indices ◽  
Physico Chemical ◽  
In Series ◽  
Mixed Stationary Phase ◽  
Equine Estrogens

The capillary gas-chromatographic retention behavior of six underivatized equine estrogens (estrone, equilin, equilenin and their corresponding 17α-diols) on a mixed stationary phase (non-polar CP-Sil 5 CB and slightly polar CP-Sil 19 CB capillary columns coupled in series) was characterized by their Kovats retention indices and steroid numbers. In order to find whether a correlation exists between the chromatographic retention and some physico-chemical properties of the compounds, their octanol-water partition coefficients and dipole moments were measured. No straightforward correlation was observed between the physico-chemical properties and the retention behavior, which suggests that the GC separation of equine estrogens is governed by some specific electron donor-electron acceptor interactions of a chemical nature.

A new approach to the prediction of gas chromatographic retention indices from physico-chemical constants

1991 ◽  
Vol 56 (10) ◽  
pp. 2042-2054 ◽  
Author(s):  
Igor G. Zenkevich ◽  
Lyudmila M. Kuznetsova
Keyword(s):  
Molecular Weight ◽  
Stationary Phases ◽  
Retention Indices ◽  
Molar Refraction ◽  
Boiling Temperature ◽  
Chromatographic Retention ◽  
New Approach ◽  
Physico Chemical ◽  
Gas Chromatographic Retention Indices ◽  
Chromatographic Retention Indices

A general approach is proposed to the calculation of gas chromatographic retention indices (RI) of organic compounds on standard polydimethylsiloxane stationary phases based on their principal physico-chemical constants such as the boiling temperature, molar refraction or molecular weight. A combination of logical criteria was established for comparing functions of the above parameters for the identification of substances whose RI values are only determined by their boiling temperatures. It is demonstrated that within homologous series, the dependence of the RI value on the boiling temperature or any additive molecular parameter (molecular weight, molar refraction, number of carbon atoms in the molecule, etc.) is nonlinear. If this dependence is taken into account, the RI value of any organic compound can be predicted with a precision comparable to the standard deviation of the statistically processed values determined in nonequivalent conditions.

scholarly journals Biological Activity of Anthraquinone Compounds of the Alcoholic Extract Propolis

2020 ◽  
Author(s):  
Mustafa Hussein ◽  
Hasan Smesam ◽  
Lamia Risan ◽  
Sareh Arjmand
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Biological Activity ◽  
Safety Assessment ◽  
Klebsiella Pneumonia ◽  
Alcoholic Extract ◽  
Bacterial Isolates ◽  
Indigenous Medicine ◽  
Propolis Extract ◽  
Ft Ir

Different products from a unique Propolis extract, Propolis (bee glue), an of resinous consistency produced by bees, has been used as indigenous medicine for the treatment of several diseases in some contrary. Safety assessment of propoils extracts with respect to antimicrobial activity against three bacterial isolates, Proteus Mirabilis , Klebsiella Pneumonia and Staphylococcus Qureus.The result showed that the main composition of the extract was Anthraquinone, the last one was responsible for the biological activity of the extract. FT-IR, UV results showed more than eight peaks for represent the main fine composition of the extract. The present study also showed that the extract has antibacterial activity against three bacterial isolates

scholarly journals Congener-specific partition properties of chlorinated paraffins evaluated with COSMOtherm and gas chromatographic retention indices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jort Hammer ◽  
Hidenori Matsukami ◽  
Satoshi Endo
Keyword(s):  
Chemical Properties ◽  
High Volume ◽  
Retention Indices ◽  
Chromatographic Retention ◽  
Linear Free Energy Relationship ◽  
Linear Free Energy ◽  
Chlorinated Paraffins ◽  
Gas Chromatographic Retention Indices ◽  
High Volume Production ◽  
Volume Production

AbstractChlorinated Paraffins (CPs) are high volume production chemicals and have been found in various organisms including humans and in environmental samples from remote regions. It is thus of great importance to understand the physical–chemical properties of CPs. In this study, gas chromatographic (GC) retention indexes (RIs) of 25 CP congeners were measured on various polar and nonpolar columns to investigate the relationships between the molecular structure and the partition properties. Retention measurements show that analytical standards of individual CPs often contain several stereoisomers. RI values show that chlorination pattern have a large influence on the polarity of CPs. Single Cl substitutions (–CHCl–, –CH2Cl) generally increase polarity of CPs. However, many consecutive –CHCl– units (e.g., 1,2,3,4,5,6-C11Cl6) increase polarity less than expected from the total number of –CHCl– units. Polyparameter linear free energy relationship descriptors show that polarity difference between CP congeners can be explained by the H-bond donating properties of CPs. RI values of CP congeners were predicted using the quantum chemically based prediction tool COSMOthermX. Predicted RI values correlate well with the experimental data (R2, 0.975–0.995), indicating that COSMOthermX can be used to accurately predict the retention of CP congeners on GC columns.

scholarly journals Preparation and Antimicrobial Activity of Chitosan and Its Derivatives: A Concise Review

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3694
Author(s):  
Luminita Georgeta Confederat ◽  
Cristina Gabriela Tuchilus ◽  
Maria Dragan ◽  
Mousa Sha’at ◽  
Oana Maria Dragostin
Keyword(s):  
Antimicrobial Activity ◽  
Low Cost ◽  
Hydroxyl Groups ◽  
Pharmacological Properties ◽  
Natural Polymers ◽  
Economic Sectors ◽  
Physico Chemical ◽  
Long Time ◽  
Resistant Strains ◽  
Strength And Durability

Despite the advantages presented by synthetic polymers such as strength and durability, the lack of biodegradability associated with the persistence in the environment for a long time turned the attention of researchers to natural polymers. Being biodegradable, biopolymers proved to be extremely beneficial to the environment. At present, they represent an important class of materials with applications in all economic sectors, but also in medicine. They find applications as absorbers, cosmetics, controlled drug delivery, tissue engineering, etc. Chitosan is one of the natural polymers which raised a strong interest for researchers due to some exceptional properties such as biodegradability, biocompatibility, nontoxicity, non-antigenicity, low-cost and numerous pharmacological properties as antimicrobial, antitumor, antioxidant, antidiabetic, immunoenhancing. In addition to this, the free amino and hydroxyl groups make it susceptible to a series of structural modulations, obtaining some derivatives with different biomedical applications. This review approaches the physico-chemical and pharmacological properties of chitosan and its derivatives, focusing on the antimicrobial potential including mechanism of action, factors that influence the antimicrobial activity and the activity against resistant strains, topics of great interest in the context of the concern raised by the available therapeutic options for infections, especially with resistant strains.

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